Combined packing and partially printing of packing material

ABSTRACT

A combined packing and partially printing system is utilized to produce a desired individually varying print on any packing unit without interrupting the packing process by which a blank of packing material is formed to any desired shape of a packing unit, on a packing device and then filled with goods. The surface of the packing material is at least partially print-coated with a layer of a photoconducting substance or blend of substances prior to being introduced into the packing device for being folded and set into the desired shape. The packing device is combined with a charging unit including means for variably adjusting the length and width of the area to be charged of the photoconducting layer on the packing material. A photographic unit is present for exposing the charged photoconducting layer by light allowed to pass through any desired character of a matrix, and a developing unit in combination with a fixing unit serve to produce the desired images of said characters at the desired partial sections of the surface of said packing material under processing. In this manner variable imprints can be applied to any desired quantity of packing units without the packing process being interrupted.

United States Patent [72] Inventor. Hans Hermann Dittner Alli der IIardt 7, 5161 Obermaubach, Germany 211 Appl. No. 843,359 [22] Filed July 22, 1969 [45] Patented Dec. 21,1971

[54] COMBINED PACKING AND PARTIALLY PRINTING 0F PACKING MATERIAL 11 Claims, I Drawing Fig.

53/131,355/100,355/17 [51] Int. Cl. G03g 15/00 [50] FieldofSearcIi 355/3,17,

[56] References Cited UNITED STATES PATENTS 2,634,565 4/1953 Currinan 53/131 3,054,339 9/1962 Marcott 355/100 3,185,777 5/1965 Rheinfrank..... 355/17 X 3,301,152 1/1967 Mayo 355/3 3,520,104 7/1970 Mizelle 53/131 Primary Examiner-John M. Horan AttorneyY oung & Thompson ABSTRACT: A combined packing and partially printing system is utilized to produce a desired individually varying print on any packing unit without interrupting the packing process by which a blank of packing material is formed to any desired shape of a packing unit, on a packing device and then filled with goods. The surface of the packing material is at least partially print-coated with a layer of a photoconducting substance or blend of substances prior to being introduced into the packing device for being folded and set into the desired shape. The packing device is combined with a charging unit including means for variably adjusting the length and width of the area to be charged of the photoconducting layer on the packing material. A photographic unit is present for exposing the charged photoconducting layer by light allowed to pass through any desired character of a matrix, and a developing unit in combination with a fixing unit serve to produce the desired images of said characters at the desired partial sections of the surface of said packing material under processing. In this manner variable imprints can be applied to any desired quantity of packing units without the packing process being interrupted.

COMBINED PACKING AND PARTIALLY PRINTING OF PACKING MATERIAL BACKGROUND OF THE INVENTION The invention relates to the artof printing a packing material and in particular to partial imprinting of characters such as letters or patterns on a packing unit such as bags or boxes or the like containers formed from webs or endless strips of paper, sheets of cardboard, aluminum foils or plastics films which are used for packing on packing machines.

At present, a technique is employed in which sheets or endless webs or strips of paper and the like packing material are printed in large quantities before they enter the packing machine and then different individual imprints are applied to the packing units by subjecting them to a separate printing process. However, this technique of the art is meant to be used for comparatively small quantities of about 500 to 1000 individual units or pieces, only. ln another system, the printing can also be done with several colors, in a dry way by the method of hot stamping. Both the known imprinting processes are relatively expensive since the plates required for the imprinting of said small quantity of units cannot be manufactured economically.

SUMMARY In accordance with the present invention, there is used a method and a system by which it is possible to apply imprints in a simple manner continuously or discontinuously to packings of very small quantities in such a way that the packing process is not interrupted by a change of the imprinted character.

The process of the invention utilizes a system for partial imprinting of letters or patterns on packing material made of paper, cardboard, aluminum foils or plastic foils which are formed in a packing device into bags, boxes or similar packing units. According to the present invention the packing material is at least partially print-coated with a photoconducting layer before it enters the packing device. The layer is charged during or after the forming and setting into shape in said packing device, and the charged layer is exposed with the help of a matrix of characters to be imprinted. Then the images of the characters are developed and fixed. Developing units and methods as well as fixing units and methods suitable for this purpose are well known in the art.

It has proved advantageous to use as photoconducting layer a Zno-layer, 2 to pm. thick, which is imprinted by intaglio. Preferably one will print ZnO and colors together in a printing machine including several inking units. It is also possible to use other printing processes such as ofi'set-print, flexoprint, letter-print, aniline-print and screen-print. Such printing processes are known in the art, and need not be described in any detail herein.

Up to now photoconducting layers for electrophotography have been produced by spread-coating a layer of a thickness of to 25 pm. on the material to be printed. The prevailing opinion was, the layers of such a thickness are necessary to obtain readable print. Surprisingly it was found however, that a spread-coating of the photoconducting material is not necessary in fact if the layer is applied by a conventional printing machine, especially an intaglio machine. Thus the thickness of the layer is reduced and layers of a thickness of 2 to 10 um. are quite sufficient to obtain a satisfactory resolution.

In this way it is possible to apply arbitrary partial imprints of photoconducting layers to large quantities of packing material and then to produce texts and patterns from different originals on them in arbitrarily small quantities.

For the photoconducting layer each of the known materials may be used. The well known mixtures of ZnO-powder of appropriate conductivity and sufficient grain size blended with well isolating resin as binding agent have proved as useful. They may contain arbitrary known color-sensibilisators such as fluorescein, eosin, rose bengale, malachite green, christalviolet or chinoline, thiacine and acridine colors.

In the process according to the invention the packing material may contain, besides the partial imprints of photoconducting layers, further colored and/or texted areas which may be obtained by any known printing process such as intaglio, aniline-print, screen-print, offset-print or the like methods. it is advantageous to use a printing device including several inking units. It is then possible to use some of the inking units for color-printing and some for the application of the photoconducting layer. Thus an especially efficient mode of operation is achieved.

Normally one printing process will be sufficient for the imprinting of the partial layer, which is to be 2 to 5 pm. thick. However, depending'on the packing material used and the resolution desired an additional second printing process may be expedient.

After the desired color and photoconducting imprints have been made on the packing material, it enters a packing device which forms it into bags, boxes or similar containers, just as desired. The electrophotographic copy on the partial areas containing the photoconducting layer may be made before, on or after the packing device.

An expedient device to be used in conjunction with the packing device in the system of the present invention, consists of a combination of a charging unit, where the width and length of the area to be charged may be varied, which may be coupled synchronously to the transport of the packing unit, an exposing unit, where the exposure may be varied depending on the transport velocity of the packing unit, a developing unit, a device with continually rotating rolls which stores developing solution and which may be pressed against the exposed photoconducting layer by a pressing device and alternatingly lifted off from it in accordance with the transport of the packing material through the packing device, and a fixing unit with a hot air blower or heating rod and/or air expelling device. It may be expedient to use instead of roll-development an elastic fiat developing form made of porous plastic with good absorption capability for the developer-solution.

To obtain a variable adjustment of the charging unit masks may be introduced which may be adjusted in the transport direction of the packing material and/or vertically to it, so that width and length of the charged area may be controlled. It may be expedient to be able to choose the adjustment by means of a switch which is coupled to the packing device.

The exposing unit will normally contain a flash device; the duration of the flash will depend on the transport velocity. For instance at a transport velocity of 10 centimeters per second it will be at most one one-thousandth of a second which would correspond to a margin of error of about 0.1 mm. The flash may be triggered by a scanning device.

As a consequence of the special spatial arrangement, developing in connection with packing machines can be only effected by contact with the development solution from one side. This has the advantage, however, that the consumption of toner is only small and quick fixing is possible because only a small amount of liquid is involved. The developing unit includes rolls or flat forms, the outside of which consists of a porous material such as porous plastic, which is able to store developing solution. A porous plastic layer of 1-10 mm. has proved sufficient for diameters of the rolls of 1-10 cm. The rolls rotate continually in order to keep the developer solution evenly distributed in the pores of the porous layer. The plastic layer is surrounded expediently by a fine metal wire screen which is electrically isolated and may be charged from 0 to 200 volts by a DC generator. By means of a pressing device such as a device including an electromagnet, the rolls or the flat developing form are pressed against the photoconducting layer and lifted off, after complete wetting of the layer has been effected, whereby the image on the layer is developed. Depending on the width of the exposed photoconducting layer, rolls in appropriate numbers and widths may be provided for and put in action simultaneously or in some definite sequence.

1 When the developing solution has been applied to the exposed areas of the photoconducting layer, the packing material which has been treated in this way is transferred to the fixing unit where the liquid of the developer is removed by a hot air blower, a heating rod, and/or an air exhauster.

The resistance of the electrophotographic reproduction against abrasion may be increased by treatment with a transparent varnish. Expediently the originals which are used in the exposing unit are slides on 16 mm. or 35 mm. film. The slides may be attached to punched cards. The punched cards may be marked for instance with the address of the customer who wishes to imprint some advertisement on the packing; they may be punched and filed accordingly. The process of the invention may be employed in an especially economical way if the slides which serve as originals for the exposure are kept on store and exchanged according to the desired arbitrarily low number of copies.

The invention may best be understood from the following detailed description thereof having reference to the accompanying drawing which is a block diagram illustrating an embodiment of the system of the invention.

To an output-table l of an ordinary packing device (not shown) there are suitably arranged a charging unit 2 including adjustable masks, followed by an exposing unit 3, a developing unit 4 combined with a continually rotating roll-device 5 and finally a fixing unit 6 with attached exhausting device 7.

Cutting, forming and setting of the packing material into the desired blanks and to the desired shape of individual packing units may be effected prior or after the blanks pass the units 2, 3, 4, 5, 6, and 7, in the direction of the arrow shown at the output-table l. The filling of the packing is expediently done at a place behind the units 6 and 7. However, arbitrary different arrangements are possible; here it is only important to arrange the units 2 through 7 in the given order and series and as close to each other as possible.

The charging unit 2, the exposing unit 3, the developing unit 4, the roll-device 5, the fixing unit 6 as well as the exhausting device 7 may be of any suitable type well known in the art, and need not be described in any detail herein.

Having thus described the principles of the invention, together with an illustrative embodiment thereof, it is to be understood that, although specific terms are employed, they are used in a generic and descriptive sense, and not for purposes of limitation, the scope of the invention being set forth in the following claims.

l claim:

I. A combined packing and partially printing system comprising in combination a supply means for continuously supplying endless strips from a packing material stock, a printing means for at least partially print-coating said strips of packing material with a layer of a photoconducting substance, a packing device for preparing the desired blanks of-said printcoated packing material and folding and setting said blanks into the desired shape of a packing unit, means for directing said endless strips of packing material from said stock through said printing means onto said packing device, a charging unit including means for adjustably varying in length and width the area of said photoconducting layer to be charged, a photographic unit for producing images of any desired character on said print-coated charged packing material, a developing unit, and a fixing unit for setting said character on said packing.

2. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a web of paper.

3. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a sheet of paperboard.

4. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a foil of aluminum.

5. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a film of plastics.

6. A combined packing and partially printing system according to claim 1 wherein said print-coating means comprises a supply for a layer of a photoconducting substance to be applied onto said packing material in an amount of about 2 to 10 pm. in thickness.

7. A combined packing and partially printing system according to claim 1 wherein said developing unit includes a continuously rotating roller squeeze-type storage tank containing the developing solution and being actuated by a lifting and forcing press.

8. A combined packing and partially printing system according to claim 1 wherein said developing unit includes a movable die plate-type storage tank containing the developing solution and being actuated by a lifting and forcing press.

9. A combined packing and partially printing system according to claim 1 wherein said fixing unit includes a hot-air blower.

10. A combined packing and partially printing system according to claim 1 wherein said fixing unit includes a heating element.

11. A combined packing and partially printing system according to claim 1, and in addition including means for synchronously timing and automatically controlling the speed of feed of the basic packing material to said packing device, the adjustment of charge to said layer of a photoconducting substance on the print-coated packing material, the time of exposure of the charged photoconducting layer and the direction and period of movement of said lifting and forcing press actuating said storage tank containing the developing solution. 

1. A combined packing and partially printing system comprising in combination a supply means for continuously supplying endless strips from a packing material stock, a printing means for at least partially print-coating said strips of packing material with a layer of a photoconducting substance, a packing device for preparing the desired blanks of said print-coated packing material and folding and setting said blanks into the desired shape of a packing unit, means for directing said endless strips of packing material from said stock through said printing means onto said packing device, a charging unit including means for adjustably varying in length and width the area of said photoconducting layer to be charged, a photographic unit for producing images of any desired character on said print-coated charged packing material, a developing unit, and a fixing unit for setting said character on said packing.
 2. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a web of paper.
 3. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a sheet of paperboard.
 4. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a foil of aluminum.
 5. A combined packing and partially printing system according to claim 1 wherein said packing material comprises a film of plastics.
 6. A combined packing and partially printing system according to claim 1 wherein said print-coating means comprises a supply for a layer of a photoconducting substance to be applied onto said packing material in an amount of about 2 to 10 Mu m. in thickness.
 7. A combined packing and partially printing system according to claim 1 wherein said developing unit includes a continuously rotating roller squeeze-type storage tank containing the developing solution and being actuated by a lifting and forcing press.
 8. A combined packing and partially printing system according to claim 1 wherein said developing unit includes a movable die plate-type storage tank containing the developing solution and being actuated by a lifting and forcing press.
 9. A combined packing and partially printing system according to claim 1 wherein said fixing unit includes a hot-air blower.
 10. A combined packing and partially printing system according to claim 1 wherein said fixing unit includes a heating element.
 11. A combined packing and partially printing system according to claim 1, and in addition including means for synchronously timing and automatically controlling the speed of feed of the basic packing material to said packing device, the adjustment of charge to said layer of a photoconducting substance on the print-coated packing material, the time of exposure of the charged photoconducting layer and the direction and period of movement of said lifting and forcing press actuating said storage tank containing the developing solution. 